Old Toro 2-stroke Lawnmower Pings

[sciphi]

The 1980's vintage Toro 2-stroke lawnmower I inherited sounds like it's pinging when it's bogged down cutting heavy grass. It's had problems in the past with the carb and fuel lines getting plugged when my grandfather didn't run it dry for a few winters. It also takes 6-7 pulls to get it to start. Once it starts, it refuses to run off the "full choke" setting on the throttle for a few minutes. After that it's fine, and readily starts up. It does smoke all the time while it's running, and smokes more when it's "pinging".

It calls for a 50:1 ratio. I'm using a little more than 2 oz. of SuperTech 2-cyle oil and 2-3 oz. of MMO in a gallon of 93 octane from a station without the E10 stickers. It's smoking a lot less on this mix. Instead of whitish blue-gray, the smoke is a dirty purple-blue.

Likely it needs a new plug, the air filter washed, and some other TLC. Thoughts?

 

[spasm3]

lean or running hot, i'd add the correct 50:1 oil amount.

 

[IndyIan]

Sounds like its running lean for some reason due to having to stay on the choke that long. My lawnboy has some play in the crank bearings and a corresponding seal leak so it makes some not good noises under heavy loads as well. Look at the plug, white isn't good!

 

[georgemiller]

Very good engines. I had one but the weak link is the coil. Very expensive and once the coil went I got rid of the mower.

 

[sciphi]

I'll check the plug. It was black the last time I checked. That never said it didn't change. I can also try adding in a little more 2-cycle oil to the gas. It'll be next week, as the grass doesn't need cutting this week.

 

[sciphi]

After doing some more research, it looks like the 6-7 pulls to start is normal for the Suzuki engine on this beast.

Model is a Toro 16585 21" cut push mower, made in 1986 by the serial number.

I'll keep running it with a touch more oil, and see where that gets me.

 

[sciphi]

After sitting for a week, I cut the grass with it yesterday. It started up on the first pull. No pinging was heard as it cut through some high grass. It didn't need to be on choke for more than ~15 seconds while it warmed up. And, very little smoke came out of it, even when it cut the thick, high patches.

Turns out I used the right amount of 2-cycle oil for the gallon of gas I got for it. It appears the MMO is doing a little cleaning. The gas is a little darker than I remember it being last week.

It looks like 93 octane gas and MMO along with the 2-cycle oil are a winner for this Suzuki engine.

 

[Johnny]

How much MMO did you mix with that gallon of gasoline?

 

[sciphi]

Originally Posted By: Johnny
How much MMO did you mix with that gallon of gasoline?
Originally Posted By: sciphi


It calls for a 50:1 ratio. I'm using a little more than 2 oz. of SuperTech 2-cyle oil and 2-3 oz. of MMO in a gallon of 93 octane from a station without the E10 stickers.


About 5-7.5x the recommended dose. Sort of a "shock" treatment.

 

[Johnny]

The proper ratio to a gallon of gasoline should be:

2.6 oz of 2-cycle oil and 2 oz of MMO

 

[sciphi]

Okay, sounds like I'm nearly on the money for ratios. I measured out 2 oz of 2-cycle oil with a little extra in short straw attached to the measuring device. So there should be ~2.5 oz of oil in there. I measured out the 2-3 oz. of MMO according to the bottle's hash marks, starting on a hash measuring every 4 oz, and ending up about halfway in between 2 hashes.

It ran great a few days ago. Maybe all it needed was fresh fuel that is known to be properly mixed.

 

[occity79]

Hey,

You may want to take the carb off and dissasseble, clean and set to factory initial settings. The symptoms also sound like it's four-stroking (sounds like pinging to some?)all the smoke is due to your 25:1 ratio (2+3~oz. mmo), most oils will smoke at that ratio. You engine could be developing a small air leak causing the need for excessive choke, the leak will get worse, of course. Make sure the govenor is set-up right and moving freely.(Best to buy a service manual if they're available)

I would be skeptical that you can find any non-ethanol gas, or at least by a tiny-tester and test for E10. Avoid Seafoam, that's just adding more alcohol, the last thing you want.

I've said goodbye to pump gas and until Stihl brings MOTO-MIX to the US of A, I'm running Sunoco Standard in all my 2 strokes ($45 for 5 gallon metal pail). I've just received a gallon of the new Mystik Ultimate 2 cycle Oil and will be using that for the rest of the fall.

Good luck with your Toro, nice mower.

 

[sciphi]

Hauling this thread up from the deep...

I dusted the old Toro off today and got it running. Yanked the carb, cleaned it a little by spraying carb cleaner into it, reassembled everything, and replaced the leaky old fuel line. 4 hours and $2 in fuel line later, it lit off and stayed running once some gas was trickled down the spark plug hole. No smoke noted with some smokeless G-Oil 2-cycle oil. Yay!